Bzoj 3624 [Apio2008] free road: And check set + spanning Tree + greedy "just have K-Bar special path"

Title Link: http://www.lydsy.com/JudgeOnline/problem.php?id=3624

Test instructions

Give you an no-show graph, n-dots, M-bar edges.

There are two kinds of sides, the species are represented by 0 and 1 respectively.

Let you ask for a spanning tree so that there are just 0 kinds of edges in this tree. Outputs the end points and kinds of each edge.

If there is no solution, the output "no solution".

Exercises

Let 0 and 1 respectively make two sides of the edge right.

Steps:

(1) Find the 0 sides that must be selected first. (Priority 1, maximum spanning tree)

(2) Add the number of 0 sides to K.

(3) Fill up 1 sides.

AC Code:

1#include <iostream>2#include <stdio.h>3#include <string.h>4#include <algorithm>5#include <vector>6 #defineMax_n 200057 8 using namespacestd;9 Ten structEdge One { A     intSour; -     intdest; -     intLen; theEdge (int_sour,int_dest,int_len) -     { -Sour=_sour; -dest=_dest; +len=_len; -     } + Edge () {} AFriendBOOL operator< (ConstEdge &a,ConstEdge &b) at     { -         returna.len<B.len; -     } - }; -  - intn,m,k; in intPar[max_n]; - BOOLFailed=false; toVector<edge>Edge; +Vector<edge>est; -Vector<edge>ans; the  * voidRead () $ {Panax NotoginsengCin>>n>>m>>K; -     inta,b,c; the      for(intI=0; i<m;i++) +     { ACin>>a>>b>>C; the Edge.push_back (Edge (A,b,c)); +     } - } $  $ voidInit_union_find () - { -      for(intI=1; i<=n;i++) the     { -par[i]=i;Wuyi     } the } -  Wu intFindintx) - { About     returnpar[x]==x?x:par[x]=find (Par[x]); $ } -  - voidUniteintXinty) - { A     intpx=find (x); +     intpy=find (y); the     if(px==py)return; -par[px]=py; $ } the  the BOOLSame (intXinty) the { the     returnFind (x) = =find (y); - } in  the voidMax_tree () the { About Init_union_find (); the sort (Edge.begin (), Edge.end ()); the     intCnt=0; the      for(intI=edge.size ()-1; i>=0; i--) +     { -Edge temp=Edge[i]; the         if(!Same (temp.sour,temp.dest))Bayi         { thecnt++; the Unite (temp.sour,temp.dest); -             if(temp.len==0) Est.push_back (temp); -         } the     } the     if(cnt!=n-1|| Est.size () >k) failed=true; the } the  - voidMin_tree () the { the Init_union_find (); the     intCnt=0;94     intSpe=0; the      for(intI=0; I<est.size () && spe<k;i++) the     { theEdge temp=Est[i];98cnt++; Aboutspe++; - Ans.push_back (temp);101 Unite (temp.sour,temp.dest);102     }103      for(intI=0; I<edge.size (); i++)104     { theEdge temp=Edge[i];106         if(!Same (temp.sour,temp.dest))107         {108             if(temp.len==0)109             { the                 if(spe<k)111                 { thecnt++;113spe++; the Ans.push_back (temp); the Unite (temp.sour,temp.dest); the                 }117             }118             Else119             { -cnt++;121 Ans.push_back (temp);122 Unite (temp.sour,temp.dest);123             }124         } the     }126     if(cnt!=n-1|| SPE!=K) failed=true;127 } - 129 voidSolve () the {131 Max_tree (); the Min_tree ();133 }134 135 voidprint ()136 {137     if(failed)138     {139cout<<"No solution"<<Endl; $         return;141     }142      for(intI=0; I<ans.size (); i++)143     {144Edge temp=Ans[i];145cout<<temp.sour<<" "<<temp.dest<<" "<<temp.len<<Endl;146     }147 }148 149 intMain () Max {151 read (); the solve ();153 print ();154}

Bzoj 3624 [Apio2008] free road: And check set + spanning Tree + greedy "just have K-Bar special path"